1. Field of Invention
The present invention relates to an image display apparatus that includes an image input device that receives a video signal, a video display that displays an image based on an input signal from the video input device, and a video signal adjusting device that adjusts a display setting of the video display based on a signal mode of the input signal.
2. Description of Related Art
Conventionally available image display apparatuses each include a video input device that receives a video signal and a video display that displays an optical image based on a video signal from the video input device. When a computer or a video cassette recorder is connected to such an image display apparatus, the video signal from the computer is displayed on a large screen such as a projection screen. This structure constitutes a computer-based multi-media presentation system.
Since a variety of computers may be connected to the image display apparatus, the image display apparatus is adjusted beforehand to match input signal modes that correspond to the computer that is likely to be connected.
Even if resolution and refresh rate are identical, a horizontal frequency of a video signal may be different from computer to computer. Even if the horizontal frequencies are identical, computers may be still different in the front porch and back porch of the horizontal blanking period and the synchronization margin of the horizontal synchronization signal. When a new computer is connected to the image display apparatus, the image display apparatus is switched on. During an operation, a user must fine-adjust settings in tracking, synchronization, display position and the like in a predetermined signal mode on the video display, each time any change takes place in the input signal, which would possibly be caused by switching the computer, from one type to another.
A system has been contemplated which performs fine adjustment of the display setting of the video display when a change takes place in the signal input to the image display apparatus. In such a system, however, the fine adjustment takes time, particularly, a tracking adjustment is time-consuming. Thus, this system is not a practical choice.